Winforms at 100% coverage

testbed/tests/widgets/test_multilinetextinput.py

@@ -64,7 +64,7 @@ async def test_scroll_position(widget, probe):
     original_width, original_height = probe.width, probe.height
 
     # The scroll position is at the origin.
-    assert probe.vertical_scroll_position == pytest.approx(0.0)
+    assert probe.vertical_scroll_position == pytest.approx(0, abs=1)
 
     # Add a lot of content
     widget.value = "All work and no play makes Jack a dull boy... " * 1000
@@ -79,13 +79,13 @@ async def test_scroll_position(widget, probe):
     assert probe.height * 2 < probe.document_height
 
     # The scroll position is at the origin.
-    assert probe.vertical_scroll_position == pytest.approx(0.0)
+    assert probe.vertical_scroll_position == pytest.approx(0, abs=1)
 
     widget.scroll_to_top()
     await probe.redraw("The document has been explicitly scrolled to the top")
 
     # The scroll position is still the origin.
-    assert probe.vertical_scroll_position == pytest.approx(0.0)
+    assert probe.vertical_scroll_position == pytest.approx(0, abs=1)
 
     widget.scroll_to_bottom()
     await probe.wait_for_scroll_completion()

winforms/tests_backend/widgets/base.py

@@ -1,5 +1,6 @@
 import asyncio
 
+from pytest import approx
 from System import EventArgs, Object
 from System.Drawing import FontFamily, SystemColors, SystemFonts
 
@@ -106,11 +107,14 @@ def assert_layout(self, size, position):
         assert self.native.Parent is not None
 
         # size and position is as expected.
-        assert (self.native.Width, self.native.Height) == size
+        assert (self.width, self.height) == approx(size, abs=1)
         assert (
-            self.native.Left,
-            self.native.Top - self.widget._impl.container.vertical_shift,
-        ) == position
+            self.native.Left / self.scale_factor,
+            (
+                (self.native.Top - self.widget._impl.container.vertical_shift)
+                / self.scale_factor
+            ),
+        ) == approx(position, abs=1)
 
     async def press(self):
         self.native.OnClick(EventArgs.Empty)

winforms/tests_backend/widgets/multilinetextinput.py

@@ -27,6 +27,30 @@ def placeholder_hides_on_focus(self):
     def readonly(self):
         return self.native.ReadOnly
 
+    def _char_pos(self, index):
+        return self.native.GetPositionFromCharIndex(index)
+
+    @property
+    def document_height(self):
+        text_len = len(self.native.Text)
+        height = self._char_pos(text_len - 1).Y - self._char_pos(0).Y
+
+        line_count = self.native.GetLineFromCharIndex(text_len - 1) + 1
+        if line_count > 1:
+            # Scale up to include the final line.
+            assert height > 0
+            height *= line_count / (line_count - 1)
+
+        return height / self.scale_factor
+
+    @property
+    def document_width(self):
+        return self.width
+
+    @property
+    def vertical_scroll_position(self):
+        return -(self._char_pos(0).Y) / self.scale_factor
+
     async def wait_for_scroll_completion(self):
         pass